Mexican leader blames candidate's killing on gangs

Mexican President Felipe Calderon is blaming drug cartels for the assassination of a front-running gubernatorial candidate.

He warns drug gangs are trying to infiltrate the election process.

Calderon said the assassination Monday of Rodolfo Torre in northern Mexico shows "organized crime is a permanent threat" and called on Mexicans to "close ranks to confront it."

He said organized crime "is trying to interfere in the decisions of citizens and in election processes."

Torre was running for governor in the border state of Tamaulipas.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

MEXICO CITY (AP) - The front-running candidate for governor in the violence-wracked border state of Tamaulipas was assassinated Monday, the first killing of a Mexican gubernatorial candidate in recent memory.

Interior Secretary Fernando Gomez Mont suggested the killing of candidate Rodolfo Torre of the Institutional Revolutionary Party, or PRI, was the work of warring drug cartels whose battles have caused hundreds of deaths in recent months in the Gulf coast state.

"These events reinforce the need to combat organized crime on all fronts," Gomez Mont told a news conference. He refused to take questions.

Gunmen ambushed Torre's vehicle as he headed to a campaign event near the state capital, Ciudad Victoria. At least four other people traveling with him were killed.

"We firmly demand a rapid investigation of these events ... and punishment for those responsible," PRI party leader Beatriz Paredes said in a statement. "Nothing is going to intimidate us."

Attacks and threats against candidates in the run-up to Sunday's elections have raised fears that drug cartels may be trying to buy off politicians, and kill or intimidate those they oppose.

Gomez-Mont said the killings "fill all of society with indignation," and pledged to "find those responsible for these detestable acts, and bring them to justice."

The other main party in Tamaulipas - President Felipe Calderon's National Action Party, or PAN - said it would suspend the remaining three days of campaigning by its own gubernatorial candidate. But PAN party leader Cesar Nava said he hoped the elections could go forward Sunday. Twelve states are holding elections for governors, mayors and local posts.

Tamaulipas is one of the main trafficking corridors for drugs heading to the U.S. market, and in recent months has been the scene of bloody shootouts between the Gulf cartel and its rival, the Zetas drug gang. The two former allies split several months ago, and have since been battling for turf.

Television footage from the scene of Monday's attack showed several vehicles and sheet-covered bodies along the side of the highway.

Torre is the highest-ranking election candidate killed in Mexico since presidential candidate Luis Donaldo Colosio, also from the PRI, was assassinated in 1994.

Seldom have candidates been hit as hard as they have in Tamaulipas this year.

In May, gunmen killed PAN candidate Jose Guajardo Varela, who had received warnings to drop his bid for the mayorship of Valle Hermoso, a town about 30 miles (50 kilometers) south of Brownsville, Texas.

Torre, 46, held a significant lead in polls as candidate for a coalition comprising the PRI and two smaller parties.

Campaigning on the slogan "So that you'll be better off," Torre was heading from Ciudad Victoria to the border city of Matamoros to accompany the PRI's mayoral candidates in the closing of their campaigns Monday.

Torre, a physician, had served as the state's health secretary from 2005 to 2009.

Supporters left dozens of messages offering their condolences on his Facebook page.